Unbiased estimation of linewidth roughness
Unbiased estimation of linewidth roughness
复制标题
线宽粗糙度的无偏估计
DOI：
10.1117/12.599981
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
B. Bunday
中科院分区：
文献类型：
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作者：
J. Villarrubia;B. Bunday
线宽粗糙度(LWR)通常简单地估计为线宽的三个标准差。图像噪声对该度量的影响包括正的非随机分量。因此，对于行业路线图所要求的光滑样品，该指标会受到偏差或“系统误差”的影响，我们估计的偏差或“系统误差”可以与粗糙度本身的大小相媲美。我们用扫描电子显微镜的粗线条图像来说明这个问题。我们建议对测量算法进行简单的更改，如果计量仪器供应商采用该算法，将允许在没有图像噪声引起的偏差的情况下估计LWR。
Linewidth roughness (LWR) is usually estimated simply as three standard deviations of the linewidth. The effect of image noise upon this metric includes a positive nonrandom component. The metric is therefore subject to a bias or "systematic error" that we have estimated can be comparable in size to the roughness itself for samples as smooth as required by the industry roadmap. We illustrate the problem using scanning electron microscope images of rough lines. We propose simple changes to the measurement algorithm that, if adopted by metrology instrument suppliers, would permit estimation of LWR without bias caused by image noise.